Unloading apparatus



Aug- 8, l951 J. M. MCCANN ET AL 2,995,260

UNLOADING APPARATUS 3 Sheets-Sheet l Filed Feb. 20, 1956 BY 54H1. G.OLSON @Ml/WW An/Wsw Aug. 8, 1961 J. M. MGCANN ETAL UNLOADING APPARATUS 5Sheets-Sheet 2 Filed Feb. 20, 1956 INVENToR. JH/v M. /l//c' CA/VN ByEARL G. OLSON @www ATTcR/vs-YJ UNLOADING APPARATUS 3 Sheets-Sheet 3Filed Feb. 20, 1956 INVEN'IOR. JH/v A4. /l//c CAN/v BY EARL G. O1. `so/vmmf@ ATTORNEY@ United States Patent O 2,995,260 UNLOADING APPARATUS.lohn M. McCann, Long Lake, and lEarl G. Olson, Minneapolis, Minn.,assignors to Vandale Corporation, Long Lake, Minn., a corporation ofMinnesota Filed Feb. 20, 1956, Ser. No. 566,696 25 Claims. (Cl. 214-17)This invention relates to new and useful improvements in apparatus forunloading silos or `the like and more particularly to new and usefulimprovements in silo unloaders of the type disclosed in Patent No.2,719,058, issued September 27, 1955.

Broadly speaking, this invention comprises a silo unloader having auextended helical collecting or gathering means positionedV upon thesurface of material within a silo for collecting or delivering materialfrom the surface o-f the ensilage to adjacent the center of the silo,said collecting means having one end in communication with the wall ofthe silo and rotatable about its other end, a central impeller means forreceiving said gathered material and continuing the movement thereof andejector means for directing it from the silo, in which new and usefulWall engaging wheel means is provided for maintaining the guidedengagement of said wall engaging end with the silo wal-1 whilepermitting ready travel with respect thereto, in which new and improveddrive hub means is provided in cooperation therewith for driving thecollecting means over the sur-face o-f the ensilage and maintaining saidend in communication with said wall for travel thereover, in which newand useful means for suspending and positioning the ejection means isprovided whereby it will be retained in discharging position during theoperation of the unloader and the travel of said collecting means, andin which new and useful cleaning means is provided in cooperation withsaid wall engaging means for loosening material immediately adjacent thewall of the silo to permit effective operation of the collecting meanswith respect thereto.

lt is therefore an object of this invention to provide a silo unloaderhaving rotary feed means adapted for travel on the surface of theensilage, and having improved means for retaining an end of the rotaryfeed means in communication with the wall of the silo and for guidingthe same for ready travel thereover.

A further object of this invention resides in the provision of a silounloader having new and useful ensilage ejection structure including anew and unique guide means for directing the ensilage from the interiorto the exterior of the silo.

Still another object of this invention resides in the means forsupporting said unique guide means.

`St-ill a further object of the invention resides in the provision of asilo unloader pendently suspended and having an ejection means forejecting ensilage from the silo, the ejection means including new andunique guide means supported from the suspension means.

Still a further object of the invention resides in the provision of thespecific chute and the particular resilient connection supporting saidchute from 4the silo suspension cable in cooperation with the limitmeans operable in cooperation with the resilient means yfor determiningthe position of the chute.

Another object of this invention -is to provide in a silo unloaderhaving a rotary gathering means adapted for rotation substantially aboutthe center of the silo and having an end in communication with the silowall, of new and useful wall wheel means for engaging the silo wall.

Still a further object of this -invention is to provide in a silounloader having means for gathering ensilage from `ICC 2, the surfacethereof andy for conveying it from adjacent the silo wall to4substantially the center thereof, the improvement of a new and uniquewall cleaning means.

Still a further object of this invention is to provide in a siloIunloader having gathering means rotatable over the surface of theensilage and a drive means for driving the same, of a drive hub meansincluding new and useful structural features.

Other and further objects of the invention reside in the specificstructural details of the apparatus as described, pictured and claimedandwill become apparent as the description proceeds.

To the accomplishment of the foregoing and related ends, this inventionthen comprises the -features hereinafter fully described andparticularly pointed out in the claims, the 4following `descriptionsetting forth in detail certain illustrative embodiments of theinvention, these being indicative, however, of but a few of the variousways in which the principles of the invention may be employed.

This invention will be described with reference to the drawings in whichcorresponding numerals refer to the same parts and in which:

FIGURE 1 is a vertical sectional view of a conventional silo showingpartially in elevation and partially in vertical section the silounloader of the present invention in position therein;

FIGURE 1A is an enlarged fragmentary elevational view, partly brokenaway showing the manner in which the ejection chute is connected to thecentral ring assembly;

FIGURE 2 is an enlarged fragmentary elevational view of one end of theejection chute;

FIGURE 3 is a vertical sectional view taken along the line and in thedirection of the vrarrows 3-3 of FIGURE l FIGURE 4 is an enlarged planview of the advance guide wheel for the unloader;

FIGURE 5 is a sectional view taken along the line and in the `directionof the arrows 5 5 of FIGURE 4;

FIGURE 6 is a fragmentary top plan view, partially in horizontalsection, of the drive hub of the instant invention;

FIGURE 7 is a fragmentary plan view of a portion of the conveying meansand showing the drive hub tie rod connected thereto;

FIGURE 8 is an end elevational view of the conveying means and showingthe dual wall cutters and pivoted wall wheels; and

FIGURE 9 is a fragmentary plan view of the structure of FIGURE 8.

Reference is now made to the drawings and specifically to FIGURES 1-3.The silo or the like in which this Iinvention is adapted to be utilizedis of upright cylindrical construction and is generally indicated by thenumeral 10. It is provided With a hollow hemispherical dome 11 and avertical cylindrical wall 12. Disposed in vertical alignment in the wall12 is a plurality of apertures 13 usually leading into a chute 14 (shownin fragmentation). The apertures 13 are provided with suitable means for retaining in place a pluralityof doors 15 for closing the aperturesto the exterior of the silo, as shown. The top and bottom of apertures13 are defined by cross-braces 16, and the apertures may be providedwith facings of any suitable sort adapted to receive and retain doors 15therein as illustrated best with reference to FIGURE 1. As seen withreference to that figure, when the ensilage or other material M isstored in the silo, the doors, which canr be hinged or are removable,are placed in their corresponding apertures and retained therein bysuitable means, usually the force of the packed material M alone beingsuilcient to so retain them. l p

While the silo has been described as a substantially upright circularcylinder, hollow, and having a semispherical roof, and with a pluralityof vertically aligned doors leading to an outside chute, the silounloader of this invention may be used with other silos or the like.While preferably, the silos or the like are circular in horizontalcross-section, they may be oval, out of round, and even substantiallysquare, octagonal, etc. so long as a substantially continuous anduninterrupted inner wall surface is provided for guiding one end of thecollecting means thereover. In such fashion, while it is preferred toprovide a roof or cover, such may be dispensed with, and while it ispreferred to support the silo unloader from means positioned on the topwall of the silo, it may in some instances be otherwise suspended solong as it is suspended from approximately the center of the silo. Thepositioning and number of the doors and apertures 13 is likewise notcritical so long as the ensilage may be directed from the interior tothe exterior of the silo.

The silo unloader generally designated 20 is suspended in communicationwith the surface of the material M so that the bottom portions of thehelical ight conveyors engage the top surface thereof as subsequentlyexplained. The unloader dangles from a suspending means 18, in thisinstance a tripod positioned upon the top edge of the wall 12 by footflanges 19. To one of the tripod legs is secured a rst pulley 21positioned so that the flexible member or cable 22 extends from a pointsubstantially underneath the apex of the tripod downwardly as sho-wn inFIGURE l. On the foot flange 19 of this leg is supported a second pulley23 extending toward the exterior of the silo. The dome 11 is aperturedat 24 to permit such extension and to permit the cable 22 to emerge fromthe cover of the silo and continue downwardly to a securing means 26 orwinch, secured to the exterior of the silo wall. Thus, the silo unloader20 will be suspended from a exible means 22 having one end securedexterior of the silo wall so that the cable may be extended or retractedfor the lowering or raising of the unloader within the silo, the otherend of the cable 22 supporting the unloader. The interior end of thecable 22 is secured to an S-hook 27 to which is also secured anadjusting cable assembly comprising three cables 28, each secured at oneend to hook 27 and at the other end to an eye-bolt 29, eye-bolt 29 inturn supporting a triangular frame member 30.

Supported upon the frame member 30, resting thereon and secured thereto,is a combination suspension and electrical contact ring assembly 31.Assembly 31 serves to support housing 33 and collecting or gatheringmeans 34 so that they may rotate together about a vertical axissubstantially at the center of the silo and also serves to supportdischarge chute 35 so that it may remain rotatively stationary withreference to the silo. Assembly 31 also provides means for connectingelectrical lead 56A to electrical lead 56B for supplying power to themotor 56.

The assembly 31, and housing 33 form no part of this invention;consequently will not be described in greater detail. Such structure isshown in co-pending application Serial No. 389,080, filed October 29,1953, now Patent No. 2,794,560.

Chute 35 is a three-sided chute of U configuration having the open mouthof the U downwardly directed throughout the arcuate and horizontallyextending portions of the chute. Chute 35 terminates at one end 36 whichend is spaced inwardly a substantial distance from wall12.

The other end 42 of chute 35 is supported on assembly 31, or may bepivoted about a horizontal axis thereto and may be of somewhat exiblematerial (in this instance sheet steel) so that end 36 may move in anarcuate direction. Preferably, it is both pivoted to assembly 31 andslightly flexible, as shown in FIGURE 1A. In this instance chute 35 ispivoted at 32 to parallel angle members 32A secured to the top surfaceof assembly 31.

While pivot 32 may be a single continuous bolt or rod through the Widthof chute 3S it is preferred to have two individual bolts, rivets, etc.,one in each of the side walls of chute 35 and opposed to provide thepivot.

Chute 35 has secured thereto at end 36 and on the top thereof a sleeve37 within which is positioned a limit means or rod 38. The rod 38 has anend 39 in engagement with the under-surface 16A of one of the members 16and a second end 40 passed through sleeve 37. The rod 38 is immovablybut adjustably positioned in sleeve 37 by a retaining means or set screw41 which set screw 41 also serves as an anchor for one end of a flexiblemember or chain 43. Chain 43 is secured to a resilient member orextension spring 44 the other end of which is secured to the S-hook 27.If desired, the chain 43 and spring 44 may extend to the next highercross brace 16, and spring 44 may be secured thereto.

Thus, it will be seen that the spring 44 in cooperation with chain 43serves to bias the chute 35 which is of flexible material or pivoted toassembly 31 so that end 36 may move substantially upwardly anddownwardly with reference to the material surface M or arcuately about ahorizontal axis approximately in the center of the silo, in a directionso that end 39 engages the under surface of the brace 16 and thusretains the chute in the position of FIGURE 1. The end 39 by engagementwith the undersurface of brace 16 determines the limit position to whichsuch biasing occurs. The effect of this is to allow the silo unloader tobe moved substantially upwardly and downwardly while retaining rod 38 ata datum position in communication with the brace 16 and etfec tivelypositioning the terminal end of the chute 36 to discharge material at apredetermined vertical position through the aperture 13 as shown. Asshown, the rod 3S, and consequently the discharge position of chute 35is centered horizontally in the aperture 16 and maintained centered bythe engagement of flanges 48 with brace 16, as further explained.

The silo unloader is of the type having a gathering arm or collectingmeans slightly greater than the average diameter of the silo with whichit is to be used as specified in said Patent No. 2,719,058, and rod 38is in only frictional engagement with the underside of the brace 16 andunder only such frictional engagement as is provided by the tensionunder which spring 44 is positioned (which is usually relatively weak)and is free to slide with refer ence to brace 16.

A torque arm 45 or stabilizing means for preventing the rotation of thechute 35 is pivoted about a horizontal axis 46 to the silo unloader andusually to the framework 30. The torque arm 45 has an end received insleeve 47 provided with downwardly depending tongs or members 48 forsecuring the sleeve 47 to a brace 16 and preventing radial or arcuatemovement thereof. To'ngs 48 of sleeve 47 are preferably positioned atone corner of an aperture 16 so that arm 45 is parallel to but offsetwith reference to chute 35 so as not to be positioned thereunder. Thetorque arm 43 in cooperation with sleeve 47 serves to secure assembly 31and chute 35 effectively against other than very limited rotary motionwithin the silo Iwhile permitting complete rotary motion of gatheringmeans 34.

The impeller housing 33 is supported from the assembly 3-1 and carriesan irnpeller 33A for receiving material gathered by the collecting armand `for engaging it and impelling it in a direction upwardly andoutwardly as determined by the confinement of chute 35 as shown by thearrows 49.

'Ihe frame 51 for supporting the gathering means geuerally designated 52has parallel major horizontal or side members 53 and 54 extending at theleft end of the unloader with reference to FIGURE 3 to support thecounterweights 54C and a platform 55 for motor 56 which drives thecentral irnpeller 33A, the drive hubs 57 and the helical augers 58 and59, the impeller being driven throughbelt 60, and the conveyors 58 and59 and drive hub 57 being driven through belt 61 through a gear trainenclosed in housing or gear box 62.

The frame 51 is of elongated rectangular shape .with major extensions 53and 5,4 and minor extensions o'r ends 513A and 54A.

The collecting means or gathering mea-ns 52 comprises the conveyors orhelical augers 58 and 59 rotating in opposite directions as indicated bythe arrows 65 and 66 in FIGURE 8. Conveyors 58 and 5'9 are journalledfo'r rotation in and supported by bearing supports 70 depen-ding frommember 54A at the right end thereof with reference to FIGURES 1 and 9,the other ends of the conveyor being journalled for rotation in andsupported by housing 62 as shown `in FIGURE 3.

`Conveyors 58 and 59 in cooperation with shield 69 serve to engage thematerial M within the silo and move it inwardly into communication withthe impeller 33A of housing 33 from whence it is ejected from the siloas shown by arrow 49.

As shown best in FIGURE 9 the member 54A of frame 51 comprises an anglemember and is off-set inwardly at its juxtaposition to conveyor 58.Co'nveyor 58 comprising flighting 58A 'and shaft 58B is thus of shorterradial extension in the Idirection of the silo wall than conveyor 59.Sharft 58B has secured to the exterior and thereof a wall cleaning means71. Conveyor 59 likewise has flighting 59A and shaft 59B, the shaft 59Balso having secured to the extension thereof a lwall cleaning means 71.vBecause of the shorter extension of conveyor 58, means 71 for conveyor58 will be radially off-set with respect to means 71 for co'nveyor 59Ias shown in FIGURE 9. Consequently, the two means in cooperation willcut a path or swath wider than if they were positioned in prolongation.

The means 71 as shown best -in FIGURE 8 comprises a plurality ofextending arms 72 positioned about a center hub 73, in this instance sixin number, and having ensilage engaging ends 74 shaped to rform asurface declined from their direction of rotation (shown by arrows 65and 66 for conveyors 59 and 58 respectively) and shaped to provide acenter circumferentially extending recess in each of arms 7-1 `as shownin FIGURE 9.

Angle member 54A as shown in FIGURE 9 includes a horizontal ange 75 onwhich is secured a wear plate 76 of like configuration but somewhatwider extension as shown in FIGURE 9 to which is secured a pivot boltassembly 78 on which is pivoted a channel member 79 having the channelilanges turned upwardly with reference to FIGURE 8.

Secured to the top edges of the flanges of channel 79 are members 80each having an elongated central aperture and having an inwardlyoverhanging end. Members 80 serve as ways in which the wheels 81 arepositioned by pivot bolt assemblies 82. Ways 80 allow the utilization ofdifferent size wheels 81 with the lunloader and allow the different sizewheels to be positioned so that the portion in communication with thewall of the silo will be substantially at the point shown in FIGURE 9 tospace the wall cleaners 71 from the wall yet position them closelyadjacent thereto for eieotive cleaning thereof.

It is noted with reference to FIGURES 8 and 9 that the pivot 78 issubstantially centered between the axis 82 of wheels y81, but not at thecenter between the shafts 58B and 59B for conveyors 58 and 59. Instead,axis 78 is spaced asymmetrically with reference thereto and rearwardlyof a center line between shafts 58B 'and 59B so that left wheel 81 withreference to FIGURE 8 is behind shaft 59B a vgreater distance than theright wheel 81 is ahead of shaft 58B.

The advance guide wheel 85 shown in FIGURES 3 and 5 is pivoted -at 86 toa bifurcated member 87 supported lupon an extending guide arm 88provided at its inner vend `89 with a clamp 89A. Guideiarm `88 isin turnsupported upon a guide' arm extension 90 secured at one end'to framemember 53A and extending as shown in FIGURE 3. It is provided at itsoutward end with a lug 91 to which is hooked the reduced end of a guidearm brace 92,'the other end of which is likewise secured to member 53 asshown in FIGURE 3. A guard rod 94 has lan end clamped to brace 92 and asecond end secured to member 53 adjacent the front wheel 81 as shown inFIG- URE 3.

Ex-tension is provided with two clamps 89A, turned in the oppositedirection with reference to clamp 89A for arm 88.

Clamps 89A as shown in FIGURE 5 are U-members with `spaced -arms 89B ofsuch extension as to engage opposite portions of the circumference ofthe rod forming arm 88 or extension 90 as the case may be and areprovided with bolt assemblies 89C Afor immobilizing the respective rodwith reference thereto. Thus bolt assemblies 89C may be loosenedwhereupon the arm 88 may be extended or retracted with reference -toextension 90 and assemblies A89C may be tightened for securelyimmobilizing the extension at that position.

As shown in FIGURE 6, the ldrive hub means generally designated 57comprises a pair of identical roughly bell-shaped members 57A and 57Bspaced as shown. Each of the hubs 57A and 57B is identical and theirconiguration will be explained with reference to hub 57B. The hubcomprises an apertured center boss 100 and enlarged circular bodyportion 101 provided with a plurality of ns or lugs 102. of triangularor gusset shape with the base of the triangle at edge 103 of the hub.The body portion -101 is hollow to its juncture with boss 100 at y104 asshown.

There is thus provided a pair of spaced bell members each having acentral apertured boss and means (pins here) whereby it may be retainedupon a hub shaft (hub shaft 105) the central apertured boss joining abody portion of the hub, the body portion of drum-like configuration,hollow and having a circular terminal edge 106 spaced with reference tothe shaft 105. The tins or gores 102 extend in a direction substantiallyparallel to the extension of the hub shaft on the outer surface of thebody 101 providing inclined members from surface 104 to edge 103.

Member 57B is placed adjacent the end of the shaft 105 and member 57Aspaced inwardly therefrom. A bearing 107 engages the end of boss `100 ofhub 57A and is positioned by spacer 108 secured to shaft 105, and isprovided with an apertured lug portion to receive the reduced hook endof tie bar 109. f

Shaft 105 has a bent end 110 which is driven by a shaft through auniversal generally designated 111 in FIGURE 3 from gear box 62.

Tie bar 109 has a second reduced end which is passed through aperturedlug 112 secured to mem-ber 54 as shown in FIGURE 7, being pivotedtherein. The pivoting of tie bar 109 to the member 54 and the provisionof universal 11i1 for -hub shaft 105 allow the dual hubs 57A and 57B toiioat upon the surface of the ensilage to thus provide substantiallycontinuous uniform traction without variances because elevation of theensilage surface.

It will be apparent from inspection of FIGURE 3 that the center ofrotation of the silo unloader 20' is subst-an,- tially at the center ofthe silo and describes a small orbit thereabout by virtue of theover-center extension of the gathering means 52. However, the center ofrotation of the drive hub 57 is displaced downwardly and leftwardly withreference thereto so that as the unloader rotates within the silo and isconfined by engagement of the silo wall 12 with wheels 81 and 85, therewill be a constant sliding of the drive hub 57 in the direction of thearrow 115.

As stated previously, the pivot assembly 58 is centered between the axis82 of wheels 81 but displaced in a trailing direction of movement withreference to conveyors 58 and 59, or on the outward end of the S-membe'r76.

It has been found through experimentation that the front wheel 81 shouldbe placed as far forward (rightward with reference to FIGURE 8) aspossible, yet as a practical matter cannot be placed so that its axis isfurther forward than the periphery inscribed by the ends 74 of wallcleaners 71. Further, it has been found that the drive hub S7 and thefront wheel S1 should be positioned in the same 90 quadrant.

The particular` configuration of the gores 102 permits such sliding witha minimum of impedance since they provide a decline in the direction inthe outward end of shaft 105.

The member 57B may in some instances, if desired, be reversed from theposition of FIGURE 6 so that boss 100 will be positioned adjacent and inabutment with member 107 occupying the position normally occupied byspacer 108 and pinned to shaft 10S by a pin passed through the holenormally occupied by the pin for spacer 108.

There is thus provided a drive hub member positioned on either side ofthe tie bar 109.

It is apparent that many modifications and variations of this inventionas hereinbefore set forth may be made without departing from the spiritand scope thereof. The specific embodiments described are given by wayof example only and the invention is limited only by the terms of theappended claims.

What is claimed:

1. In a silo unloader or the like having -a rotary gathering means,wheel means for engaging the wall of the silo and for spacing saidgathering means with respect thereto and for travel thereover, saidwheel means including at least two spaced wheels, means supporting saidwheels in fixed spaced relation, and said last means being pivotallysecured to said gathering means.

2. The structure of claim 1 in which said last means is pivotallysecured to said gathering means at a point substantially equidistantfrom the axis of rotation of said Wheels.

3. The structure of claim 1 in which said means supporting said wheelscomprises an elongated member, means providing an elongated aperture ateach end thereof, and at substantially right angles thereto, and one ofsaid wheels being adjustably positioned in each of said elongatedapertures.

4. The structure of claim l in which said gathering means has a leadingAedge and a trailing edge and a frame member providing an outwardlyoff-set portion in the direction of said trailing edge and said meanssupporting said wheels is pivoted to said olf-set portion.

5. The structure of claim 1 in which said gathering means includes arotary ensilage engaging means having a leading edge and a trailingedge, a wall cleaning means axially aligned therewith positionedexterior of said rotary ensilage engaging means and likewise providing aleading edge and a trailing edge, said wall cleaning means comprising amember rotatable about a horizontal axis, said spaced wheels providing aleading wheel and a trailing wheel, and the axis of rotation of saidleading wheel being positioned not substantially outside a zone definedby the axis of rotation of said wall cleaning means and the leading edgeof said wall cleaning means.

6. The structure of claim 1 in which said gathering means includes apair of elongated ensilage engaging means each having an interior endand an exterior end adapted to be positioned adjacent the wall ofthesilo, said wheel means includes a leading wheel and a trailing wheelWith reference to the normal direction of travel of said gathering meanswith reference to the Wall of the silo, one of said pair of elongatedensilage engaging means providing a leading means journalled forrotation about a horizontal axis, and the axis of rotation of saidleading wheel being positioned substantially not further in said normaldirection of travel than the peripheral extension of leading means andsubstantially not further in a direction opposite thereto than the `axisof rotation of said leading means.

7. The structure of claim 1 in which said gathering means is providedwith an exterior end adapted to be positioned adjacent the wall of thesilo and an interior end substantially at the center thereof about whichit is ladapted to be rotated, drive means positioned behind saidgathering means for the rotation thereof, said wheel means providing aleading wheel and a trailing wheel, and said drive means and saidleading wheel being positioned substantially in the same ninety degreequadrant.

8. In a silo unloader adapted to be used in a silo having a lateralaperture with a top horizontal edge, and pendently suspended in the siloby flexible means, the improvement comprising a chute means secured atone end to said unloader and having means at the other end for engagingsaid edge, and resilient means secured to said flexible means forbiasing said means into communication with said top edge.

9. The structure of claim 8 in which said chute terminates short of thewall of the silo and extending rod means secured thereto is provided forengaging said top edge.

10. In a silo unloader having a drive hub means for engaging the surfaceof the ensilage for the driving thereof, the improvement comprising saiddrive hub means being of outwardly and gradually diminishing peripheryfrom the interior to the exterior edge thereof and said drive hub meansincluding a plurality of cleats for engaging the ensilage, said cleatsbeing gradually declined in the direction of the silo wall.

11. The structure of claim l0 in which said drive hub means includes twospaced hubs, each having `a plurality of said cleats.

12. In a silo unloader having a drive hub means for engaging the surfaceof the ensilage for the driving there of, the improvement comprising twospaced drive hubs axially aligned upon a common shaft to provide aninside and an outside hub, said inside hub having a plurality of cleatsfor engaging the ensilage, said cleats being gradually declined from theinterior to the exterior edge of said hub, and said outside hub having aplurality of cleats for engaging the ensilage, said cleats Ibeinggradually declined from the interior to the exterior edge of said hub.

13. In a silo unloader having a drive hub means for engaging the surfaceof the ensilage for the driving thereof, the improvement of two spaceddrive hubs positioned upon a common substantially radially extendingshaft, a tie bar positioned to said unloader and to said shaft betweensaid drive hubs, said shaft being journalled for rotation with referencethereto, said spaced drive hubs each including a plurality of cleats forengaging the surface of the ensilage and said cleats each graduallydeclined from the interior to the exterior edge thereof.

14. In a. silo unloader having a drive hub means for engaging thesurface of the ensilage for the driving thereof, the improvement of asubstantially radially extending shaft on which said drive hub means ispositioned, said shaft being connected to said unloader by a universaljoint means for the rotation thereof, a tie bar means having an endconnected adjacent the extending end of said shaft and in which saidshaft is journalled for rotation, said tie bar being connected to saidunloader at a position spaced with reference to said universal adistance substantially equal to the radius of the silo with which theunloader is to -be used and pivotally connected thereto whereby saiddrive hub means may oat with reference to the unloader.

l5. In a silo unloader having an advance guide wheel supporting framepositioned ahead of a gathering means and in the path of rotationthereof, the improvement of said advance guide wheel means comprising afirst extending arm having turned bifurcated means, a second extendinganni supporting said advance wheel and having turned bifurcated meansturned in a direction opposite to said turned bifurcated means of saidiirst extending arm, said rst land second extending arms each beingrespectively adjustably positioned in the turned bifurcated means of theother and means whereby said =rst and second extending means may beclamped in adjusted position.

16. In a silo unloader having a gathering means with an end adapted toengage the wall of a silo and for conveying material toward the centerof the silo, the improvement comprising a wall cleaning wheel meanspositioned adjacent said silo wall and comprising a plurality of spacediinger means rotatable about a horizontal axis, each of said fingermeans having a central recess extending inwardly from the exterior endthereof and in the direction of rotation.

117. The structure of claim 16 in which each of said nger means has anensilage engaging surface inclined in the direction of rotation.

18. In a silo unloader having a gathering means with an end adapted toengage the wall of la silo and for conveying material toward the centerof the silo, the improvement comprising two wall cleaning wheel meanspositioned in non-tracking relation.

19. In a silo unloader having a drive hub means for engaging the surfaceof ensilage for driving thereof, the improvement comprising said drivehub means comprising a drumlike member, axially extending gores securedto the exterior of said dru-mlike member in parallel relationship, saidgoes each having a slanting outer edge that declines regularly from oneend to the other end of said member and said edges all declining in thesame direction.

20. In a silo unloader having means positioned at the center of the silofor receiving and ejecting material from the silo, the improvementcomprising means for guiding the material from said receiving andejecting means to :the exterior of the silo including a chute, saidchute being configured to receive said material in a substantiallyvertical direction and for guiding it from the silo in a substantiallyhorizontal direction, said chute being so constructed yas substantiallyto retain said configuration, and said chute being pivoted at `its innerend to said receiving and ej ecting means.

21. The structure of claim 20 in which said chute comprises `bottom andside walls forming a U-shaped channel opening in the direction of thematerial and pivoted to said receiving and ejecting means adjacent thebottom wall.

22. In a silo unloader or the like having a rotary gathering means,wheel means for engaging the wall of the silo for travel thereover andfor spacing said gathering means with respect thereto, said wheel meansincluding at least two spaced wheels, said gathering means including arotary ensilage engaging means, a wall cleaning means axially alignedtherewith and positioned exterior of said rotary ensilage engaging meansand providing a leading edge and a trailing edge, said wall cleaningmeans comprising a. member rotatable about a horizontal axis, saidspaced wheels providing a leading wheel and a trailing wheel andthe axisof rotation of said leading wheel being positioned not substantiallyoutside a zone defined yby the axis of rotation of said wall cleaningmeans and the leading edge of said wall cleaning means.

23. The structure of claim 22 further characterized in that saidgathering means includes a leading and trailing rotary ensilage engagingmeans, a leading and trailing wall cleaning means axially alignedtherewith and the axis of said leading wheel is so positioned withreference to the axis of said leading wall cleaning means.

24. In a silo unloader having a gathering means with an end adapted toengage the wall of a silo and for conveying material toward the centerof the silo, the improvement comprising a leading wall cleaning meansand a trailing wall cleaning means and said leading wall cleaning meanshaving an exterior edge surface positioned inwardly of the exterior edgesurface of said trailing wall cleaning means.

25. In a silo unloader or the like having a rotary gathering meansadapted to engage the wall of a silo and for conveying material radiallyof the silo, including a leading and trailing rotary ensilage engagingmeans, wheel means for engaging the wall of a silo for travel thereoverand for spacing said gathering means with respect thereto, la wallcleaning means axially aligned with each of said ensilage engaging meansand positioned at one end thereof, and adjacent said silo wall, saidwall cleaning means comprising members lrotatable about substantiallyparallel, substantially horizontal axes, one of said wall cleaning meansproviding a leading wall cleaning means and the other of said wallcleaning means providing a trailing wall cleaning means, the improvementcomprising at least a portion of one of said wall cleaning means beingsubstantially axially oli-set with reference to the other of said wallcleaning means.

References Cited in the file of this patent UNITED STATES PATENTS2,580,306 -Leach Dec. 25, 1951 2,595,333 Clapp May 6, 1952 2,615,594Clapp Oct. 2,8, 1952 2,671,696 McLean Mar. 9, 1954 2,674,210 Holub Apr.6, 1954 2,678,241 Miller May 1, 1954 2,719,058 VanDusen Sept. 27, 19552,756,112 Knutson July 24, 1956 '2,761,742 Hintz Sept. 4, 1956 2,788,247Chapman Apr. 9, 1957 2,794,560 Buschbom June 4, 1957 2,801,885 HarrisAug. 6, 1957 2,858,033 Hofer Oct. 28, :1958

